Improvement in rock-drilling sviachines



E. S; WINCHESTER."

Rock-Drilling Machine.

Patented July 13, 1875.

7 I vI W? amass.

MPEIERS, PHOTO-LITHDGRAFHEH, WASHINGTCN D 0 EDWARD S. WINCHESTER, OFBOSTON, MASSACHUSETTS.

IMPROVEMENT IN ROCK-DRILLING MACHINES.

Specification forming part of Letters Patent No. 165,646, dated July 13,1575;- application filed April 30, 1875.

To all whom it may concern Be it known that I, EDWARD S. WINCHES- .TER,of Boston, in the. county of Suffolk and which the following is aspecification:

My invention relates to engines for drilling rocks, usually termedrock-drills; and the invention consists in a novel construction of thevalve and its ports, to prevent the entrance of foreign substancesthrough them into the steam-passages. It further consists in thecombination, with the spring-arms of the valve, of rubber or otherelastic material, 'to increase their durability and prevent breakage;and it further consists in a novel construction and arrangement of theparts, whereby the engine is rendered less liable to stop in consequenceof the valve not making its full movement, all as hereinafter more fullyset forth.

Figure l is a longitudinal section. Fig. 2 is a side elevation of thevalve detached; and Fig. 3 is a transverse section of the same, taken onthe line :c w of Fig.2.

In rock-drilling engines it often happens that fragments of rock orother foreign material accidentally enter the steam-passage when thehose or pipe is disconnected, and when the engine is started thesefragments are driven into the ports or openings of the valve, and,catching between the edges of the valve and the passages in thecylinder, either break the latter or stop the engine, necessitating lossof time and repairs. To obviate this 1 construct my valve as representedin the drawings. As there shown, the passages e, which lead to the portsI), consist of a series of holes of less diameter than the port itself,so that nothing can enter that will not readily escape from the ports b.These holes may be round, as represented, or the may be oval; or theymay be united, so as to form a narrow slot, less in size than the portb, though I prefer a series of holes instead of a slot, as they willobviously operate more perfectly to prevent the entrance of solidparticles. These holes 6, it will be observed, enter the ports b atnearly a right angle, so that any slender object, such as a nail orsmall bolt, which might enter the holes 6, cannot work through, as itsfront end would strike against the wall of the port, which would preventits further passage. As the passages c are to be made of a size equal tothe passages a, leading to the cylinder, it will be seen that anysubstance that can pass through the openings 6 will pass readily on intothe cylinder, where particles of such size cannot create any suddenbreakage, and from whence they can be removed at will.

The body of the valve A is cylindrical in form, made solid, and isseated in a correspond-iuglyformed cavity, as shown in Fig. 1. Thatportion of the surface of the valve between the openings 6 and the portsI), and designated by the letter d in Figs. land 3, is made equal inextent, or greater than the semicircular wall f, against which it works,as shown in Fig. '1, so that, whatever position the valve may occupy,the edge of the openings 6, will never pass the edge of the wall f, andhence any object that will enter the openings 6 cannot be carried pastthe edge of the walls f, and by that means I guard against accidentsfrom that source.

Another difficulty with this class of engines is their liability to stopat the forward stroke of the piston, in consequence of the drillstriking the rock before the piston D has movedfar enough to throw thevalve a sufficient distance to admit the steam or air for the reversestroke. To obviate this difficulty I arrange the inlet-passage O in sucha posi-- tion in relation to the broad flat armor lever O of the pistonD that the steam or compressed air, as it enters, will strike directlyagainst the arm G, and thus assist to throwit forward, this arrangementbeing shown in Fig. 1. It will be observed, also, that the groove at thecenter of the piston D, in which the end of. the arm 0 plays, is of sucha size that when the piston has completed its stroke the arm 0 has stilla short distance to move in order to complete its stroke, thisadditional movement of the arm being accomplished by the momentum of thevalve and its arm, so that it the piston should stop a little short ofits full stroke, the valve will continue its motion until its stroke iscompleted, thus preventing the engine from stopping, as it otherwisewould. On its back stroke there sured, so as to reverse the stroke andinsure the continuous operation of the engine. The arm 0 of the valve ismade, as represented in the drawings, of a flat piece of steel dividedinto two separate curved parts, which operate as a spring, so that whenstruck by the pisr ton there will not be the liability of breakage bythe suddenconcussion, and also less jar than there would otherwisebe;and to still further lessen the liability of breaking these spring-arms,and to render them more durable, I interpose between them a piece ofrubber, P, as shown in Figs. 1 and 3. Instead of rubber, any otherelastic material may be used, such as leather, or even wood, withbeneficial results; but I consider rubber best adapted for the desiredpurpose.

By these several improvements I am enabled to produce an engine that isfar less liable to become deranged or stopped, that is more perfect inits operation, and also more durable.

Having thus described my invention, what I claim is- 1. The solidplug-valve provided with the steam-passages 6, less in diameter than theports I), to prevent the entrance of fragments of rock or other foreignmaterial.

2. The solid plug-valve provided with the ports I), with thesteam-passages 0 arranged at right angles thereto, whereby elongatedarticles entering the passages e are prevented from passing through theports I), as set forth.

3. In combination with the oscillating valve provided with the arm 0,the inlet-passage 0, arranged to deliver the infiowing steam or airdirectly against said arm, and thereby assist in completing the fullmovement of the valve, whereby the engine is prevented from stopping onits forward stroke when the piston stopsv short of its full movement, asset forth.

EDWARD S. WINCHESTER.

Witnesses W. O. DODGE, DONN TWITOHELL.

